Sometimes a substance, device or a part of human body is held between the inner periphery of an opening area and a moving element or member (e.g., a vehicle window or door such as a sliding window or door) which is adapted to be moved for closing the opening area. To prevent damage of the substance or device, or injury to the part of the human body resulting from such a sandwiched condition, the moving member is designed to be reversed by operation of the drive device for preventing the sandwiched condition. Such a device is disclosed in, for example, Japanese Patent Laid-Open Publication No. Hei. 8-260810 published without examination on Oct. 8, 1996.
In this device, the sandwiched condition is recognized when a change of rotational speed of an electric motor which moves the moving member is found. When the moving body is in the form of a sun-roof, a power window pane, or a slide door which is mounted on a vehicle, when the vehicle runs on a rough road or a sloping road, the rotational speed of the motor changes, with the result that the moving body which is in the course of closing the opening area is reversed in spite of no fear of the sandwiched condition.
Accordingly, a need exists for a device for preventing the sandwiched condition for vehicles which is free from the foregoing drawback and disadvantage.